Method of bending conduits



Feb. 26, 1935. D F. N EWMAN METHQD OF BENDING CONDUITS Filed June 29, 1934 49M fii mtorney.

n a W P e cl c N ha nm e D flat sided conduits formed 'atented Feb. 26, 1935 UNITED STATES METHOD OF BENDING Delbert F.

Newman, Schenectady,

CONDUITS N. Y., assignmto General Electric Company, a corporation of New York Application June 29,

1934, Serial No. 733,032

10 Claims. (01. 153-32) My invention relates to methods of bending conduits, and particularly to methods of bending between sheets of metal.

Conduits for heat exchange devices, such as evaporators and condensers chines. are frequently constructed by indentations in one of two metal sheets and by securing the sheets together in face engagement to provide a passageway between the sheets. In some constructions it becomes desirable to bend the sheets at sharp angles to obtain the required shape, and in such cases considerable difficulty is encountered in preventing restriction of the passageways at the places where they cross the bends in the sheets. This is particularly true of passageways and conduits formed with one round or curved side and one flat side, as is a common practice in the construction of refrigerator evaporators.

Accordingly, it is an object of my invention to provide a method for bending a conduit having a flat side in such a manner that there is substantially no restriction of the passageway therethrough.

Further objects and advantages of my invention will become apparent as the following description proceeds, and which characterize my invention will be pointed out with particularity in the claims annexed to and forming a part of this specification.

For a better understanding of my invention reference may be had to the accompanying drawing, in which Fig. 1 is a perspective view of a sheet metal refrigerator evaporator provided with passageways, and constructed in accordance with my invention; Fig. 2 is a detail perspective view of two sheets formed in accordance with my invention prior to their being secured together and bent; Fig. 3 is a sectional elevation through the passageway formed between the sheets shown in Fig. 2 after they have been secured together, and Fig. 4 is a sectional view of the sheets shown in Fig. 3 after they have been ben In Fig. 1 I have shown a flooded type refrigerator evaporator comprising two sheets 10 and 11 secured together in face engagement, the sheet 11 being provided with elongated rounded indentations or corrugations cooperating with the flat portions of the sheet 10 to form sinuous passagertions 14 and 15 of the evaporator respectively, and which communicate with each other through a The sheets 10 and 11 are bent at a sharp angle along a line 1'1. Liquid refrigerant is supplied to the evaporator from other suitable source, through a conduit 18 and flows into the passageway 13 at 19' and thence upwardly and the passageways whichit flows through a connection 20' into a header 21, which is substantially liquid refrigerant, so that the liquid level is above the passage 12. Liquid refrigerant circulates from the header 21 to a tube 22 and back to the 10 conduit 13 through a connection 23. The refiowing through the conduits 12 and 13 absorbed, and the vapor-. ized refrigerant collects above the liquid level in the header 21 from which it is withdrawn through 15 a suction tube 24 and is returned to the The refrigerant evaporator shown is of construction described and ing application of Christian Steenstrup, No. 733,044, filed June 29, 1934, and assigned to 20 the General Electric Company, assignee of my present invention. I, therefore, do not herein claim anything shown or described in said Steenstrup application, which is to be regarded as prior art with respect to this application, my in- 25 vention relating to methods for bending flat sided conduits, such as those employed in the evaporator of the said Steenstrup application.

When the sheets are bent in forming the upper and lower porti 14 and 15 at the desired an angle, it is necessary to provide some arrangement for preventing the restriction of the my invention, therefore, I provide bulges arranged along the passageways at the line of bending in such a 35 that the passageways may be bent at a without reducing their cross-sectional area and thereby restricting them.

Referring now to Fig. 2 I have shown portions of the sheets 10 and 11 adjacent the line 1'? along 40 which the sheets are to be bent forming the evaporator shown in Fi The passageways 16 are formed by providing corrugations in the sheet 11 transversely of the line 1'7. In orderto prevent caving in and restricting of the passageway 16 during bending, I provide a-bulge 25 in the corrugation at the line of bending, a downwardly extending bulge 26in the sheet 10 opposite the bulge 25 to counteract the caving in effect in the sheet 10 opposite the corrugation 50 along the line of bending. I also provide additionalbulges 2'! in the sheet 11 closely adjacent either side of the bulge 25 along the corrugation 16 in order to obtain a more symmetrical bend .inthe bulge 25. The sheets 10 and 11 are then 55 e method of forming a tween two sheets transversely of th passageway besecured face to face and bent e passageway formed therein,

DELBERT F. NEWMAN. 15 

